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Distribution and quantitative development of aquatic macrophytes in relation to sediment characteristics in oligotrophic Lake Kalgaard, Denmark
Author(s) -
SANDJENSEN KAJ,
SØNDERGAARD MORTEN
Publication year - 1979
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/j.1365-2427.1979.tb01481.x
Subject(s) - macrophyte , biomass (ecology) , aquatic plant , environmental science , sediment , ecology , total organic carbon , eutrophication , perennial plant , nutrient , biology , paleontology
SUMMARY. The distribution and quantitative development of aquatic macrophytes have been studied in oligotrophic Lake Kalgaard, Denmark. The vegetation is dominated by isoetid species, which are widely distributed (about 40% of the lake bottom) compared to emergent and floating‐leaved macrophytes (about 4%). Littorella uniflora dominates at depths of 0–2 m and Isoetes lacustris from 2.0 to 4.5m. Within the colonization area the mean midsummer biomass of Littorella is 112g organic dry weight m −2 and that of Isoetes, 66 gm −2 . The total biomass of these two species constitutes 99% of the biomass of submerged macrophytes. The perennial Littorella shows only small seasonal biomass variations. The vegetational biomass, the above‐ground fraction of the biomass, and the weight of individual plants all increased with the organic content of the sediment at water depths from 0 to 0.75 m. At the same time the interstitial concentrations of carbon dioxide, extractable inorganic nitrogen, and exchangeable inorganic phosphorus increased, thus supporting the hypothesis that an increasing organic content of the sediments at this low level creates a physiologically richer medium for the plants. The isoetid growth form is discussed in relation to the chemical environment of oligotrophic, softwater lakes.